2,3-Epoxypropyl modifiers

Mechanical properties (57) have been measured for epoxies to which 2,3-epoxypropyl modifiers, e.g., bis(2,3-epoxypropyloxy) neopentane, were added. Increases in impact strength were noted for all 2,3-epoxypropyl modifiers, but tensile strength was either increased or reduced depending on the individual modifier. In most oases viscosity was reduced and and deflection temperature under load were always reduced. For nearly all the 2,3-epoxypropyl compounds tested, fracture toughness was increased. 

The 2, 3 -epoxypropyl jS-glycoside of di(N-acetyl-D-glucosamine) where R is N-acetyl glucosamine specifically inactivates hen lysozyme and several other bird lysozymes (Maron et al. 1972). The residue of hen lysozyme specifically modified by VIII is asp. 52 (Eshdat et al. 1973). X-ray analysis reveals that the two glucosamine residues of the affinity label occupy subsites B and C of the substrate binding cleft (Moult et al. 1973). The synthesis of the affinity label was accomplished by the most general procedure for the synthesis of epoxides, namely oxidation of alkenes with peroxyacids. 

Before the introduction of site-directed mutagenesis, chemical modification was the predominant means of altering a specific amino acid the earliest report with lysozyme was from Parsons and Raftery (241), who prepared the ethyl ester derivative of Asp-52 by reaction with triethyloxonium fluoroborate the modified enzyme lost catalytic function but not substrate affinity. An ethyleneimine reaction product of Asp-52 has also been prepared with similar effects on catalysis (242). Sharon and co-workers modified and then regenerated Asp-52 to eliminate concern that inactivation results from experimental manipulation rather than specific amino acid modification (243, 244). Thus, Asp-52 was first esteri-fied with an epoxypropyl-jS-glycoside derivative of di-(/V-acetyl-D-glucosamine), then reduced to homoserine or hydrolyzed to return the free aspartate. Both the... 

Delsette 101. See Adipic acid/epoxypropyl diethylenetriamine copolymer Delta 7393, Delta SD 7393. See Food starch, modified... 

Epoxies can be modified to have low energy surfaces so that they can function in conjunction with silicone-release coatings. For this application, three types of block copolymers (53), each of which consisted of two blocks, were used as surface modifiers. One bloek was a random copolymer of methyl methacrylate (MMA) and 2,3-epoxypropyl methacrylate (GMA), the other was a polymer of lH,lH,2H,2H-heptadecafluorodeeyl acrylate (PFA) which has the following structure. 

There are various modified forms of dextran available (Fig. 2.5). Nichifor et al. have widely reported about the fabrication of amphiphilic cationic dextrans, formerly crosslinked wifli epichlorohydrin or not, by replacing them with groups alike to the mentioned ones however in which one of the quaternary ammonium substituent s was an alkyl chain between C2 and C16 instead of methyl [24]. In this circumstance the reagent active for cationization was a 2,3-epoxypropyl alkyl dimethyl ammonium chloride derived from epichlorohydrin and a dimethyl alkylamine [24]. Products with a DS between 0.18 and 0.94 were derived The kinetic of the reaction of polysaccharides, with epichlorohydrin and various tertiary amines was investigated [24], by quantification of reagents and products in the reaction mixture with or without the presence the polysaccharide, at regular intervals. They reported fliat the use of cyclic amines e.g. 1-methyl-imidazol or 1,4-diazabicyclo [24] octan as catalysts together with another tertiary amine, used for the substitution, was not... 

Nagel et al. (2007) synthesized a thermoresponsive random copolymer of poly(N-isopropylacrylamide)-co-poly(vinylferrocene)-co-poly(mefhacrylic acid-2,3-epoxypropyl ester) by radical polymerization using 2,2 -azodiiso-butyronitrile (AIBN) as the initiator. The copolymers were then attached to a cysteamine-modified gold electrode surface via reaction between the epoxy group of the copolymer and the amino group on the electrode surface... 

---